Hard question to answer straight out. If you are flying indoors with limited space the 7.4 is probably all you need. If it is a large area with very high cellings than 11.1 will have more advantage. Length of time on either setup is determined by your use of the throttle. The 11.1 setup will shorten the life of your motor if you run full out the majority of the time. If all of your li-poly's are the same amperage then pick the least number of cells to accomplish the type of flying you do.
Hope this helps. If you get a chance go to the Ezone forums and look at the forum on Ulitmate Minis, very informative.
Harry
